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  • On the high-temperature oxidation of nickel -

    Cited by: 167
  • The oxidation kinetics of thin nickel films between 250 ...

    IntroductionExperimental MethodsResults and DiscussionAcknowledgementsThis manuscript is organized in the following way. First the defect chemical models of undoped and donor-doped NiO are described, and the oxidation theories are summarized. Then the experimental results on the oxidation of Ni films are presented, and the importance of grain boundary diffusion is shown. Attempts to accelerate the oxidation rate constant by Cr-doping and the difficulties of this approach are discussed.
  • The oxidation of nickel at reduced pressures -

    1973-1-1  According to simple kinetic theory the rate of formation of SOs is directly The oxidation of nickel at reduced pressures 333 related to the concentration of sulphur and the pressure of oxygen. Since the latter is maintained constant the SOs peak height is proportional to the sulphur concentra- tion at the surface of the foil.

  • High Temperature Pressure Oxidation of a Low-Grade

    2020-3-26  Nickel concentrate (received dry) from Poseidon Nickel Limited (Subiaco, WA, Australia) was screened to 75 m to generate the sulfidic feed material. Pressure oxidation was conducted at 250 C using a 1 gallon titanium Parr autoclave with a dual pitched blade impeller driven at a speed of 750 rpm

  • Effect of Oxygen Pressure on Internal Oxidation of

    2019-9-22  The oxidation behavior of solid-solution nickel-aluminum alloys was studied at four levels of oxygen pressure ranging from a partial pressure of 10 −4 atmosphere to a total pressure of 10 atmospheres. Three such alloys containing 1.04, 3.90, and 6.40 atomic percent (a/o) Al were oxidized at 1000 C for times of 6.25, 25, and 100 hours.

  • A study of oxidation kinetics of nickel metal in flowing ...

    2013-8-31  A STUDY OF OXIDATION KINIQICS OF NICKEL METAL IN FLOWING AIR AND OXYGEN-NITROGEN MI-S By D. J. Progar and B. W. Lewis Langley Research Center A study was made of the oxidation kinetics of nickel metal sheet in flowing air and in oxygen-nitrogen mixtures of varying composition.The study covered the temperatures 1500° F, 17>0° F, 2000° F, 2250° F, and 2500° F

  • Oxygen Transport during the High Temperature

    The high temperature oxidation of nickel has been investigated in air under atmospheric pressure in the temperature range 600–900°C. The oxidation kinetic curves deviate from the parabolic law for temperatures over 800°C. The observation of scale morphologies and the use of two stage oxidation experiments under 16O2/18O2 atmospheres showed that oxygen transport through the NiO scale had

  • Pressure Oxidation Leaching Process

    2020-7-24  Batch Autoclave Laboratory Procedures: The vessel used for the laboratory pressure oxidation process was a two-liter Parr titanium autoclave with dual impellers.It was heated and cooled externally and was pressurized with commercial-grade oxygen. A positive bleed of offgas was maintained in each test; the rate was measured in the offgas after the steam was removed with a condenser and

  • Effect of Oxygen Partial Pressure on Oxidation of Iron at ...

    2018-6-9  The oxidation of iron was investigated by Rutherford backscattering spectroscopy at 573 K under the oxygen partial pressure from 10-1 to 105 Pa for 3-24 h. In the first stage of oxidation, thickness of the oxide film reached the maximum around 1 Pa. In the second stage the oxidation obeyed the parabolic rate law.

  • Pressure Oxidation of a Refractory Sulfide

    2020-7-20  Pressure oxidation of the refractory sulfide/carbonaceous ores has gained world-wide acceptance. Compared with roasting, pressure oxidation yields higher gold extractions from ores or concentrates and enables better handling of environmentally sensitive impurities. Normally, gold is extracted from neutralized autoclave leach residue by cyanidation.

  • High Temperature Pressure Oxidation of a Low-Grade

    High temperature pressure oxidation of a low-grade nickel concentrate was examined to demonstrate the potential benefits and shortcomings of this approach. The high iron sulfide content ensured that acid generation was much greater than for higher grade concentrates. This results in the formation of basic iron sulfate phases and a significant amount of sulfuric acid.

  • High Temperature Pressure Oxidation of a Low-Grade

    2020-3-26  Abstract: High temperature pressure oxidation of a low-grade nickel concentrate was examined to demonstrate the potential benefits and shortcomings of this approach. The high iron sulfide content ensured that acid generation was much greater than for

  • Effect of Oxygen Pressure on Internal Oxidation of

    2019-9-22  The oxidation behavior of solid-solution nickel-aluminum alloys was studied at four levels of oxygen pressure ranging from a partial pressure of 10 −4 atmosphere to a total pressure of 10 atmospheres. Three such alloys containing 1.04, 3.90, and 6.40 atomic percent (a/o) Al were oxidized at 1000 C for times of 6.25, 25, and 100 hours.

  • Pressure Oxidation Leaching Process

    2020-7-24  Batch Autoclave Laboratory Procedures: The vessel used for the laboratory pressure oxidation process was a two-liter Parr titanium autoclave with dual impellers.It was heated and cooled externally and was pressurized with commercial-grade oxygen. A positive bleed of offgas was maintained in each test; the rate was measured in the offgas after the steam was removed with a condenser and

  • Pressure Acid Leaching of Nickel Laterites: A Review

    High temperature pressure oxidation of a low-grade nickel concentrate was examined to demonstrate the potential benefits and shortcomings of this approach. The high iron sulfide content ensured ...

  • Oxidation kinetics of copper at reduced oxygen partial ...

    2015-6-17  quantitative understanding of the oxidation formation process a literature studywas conducted regarding the oxidation of copper, see section 2. This revealed that although the oxidation kinetics of copper is a well studied area the oxidation kinetics below an oxygen partial pressure of 0.1 %in an inert gas atmosphere is still not fully mapped out.

  • High Pressure Acid Leach - Caldera Engineering

    High Pressure Acid Leach (HPAL) is a process used to extract nickel and cobalt from laterite ore bodies. The HPAL process utilizes elevated temperatures (roughly 255 degrees Celsius), elevated pressures (roughly 50 bar or 725 psi), and sulfuric acid to separate nickel and cobalt from the laterite ore.

  • Pressure Oxidation of a Refractory Sulfide

    2020-7-20  Pressure oxidation of the refractory sulfide/carbonaceous ores has gained world-wide acceptance. Compared with roasting, pressure oxidation yields higher gold extractions from ores or concentrates and enables better handling of environmentally sensitive impurities. Normally, gold is extracted from neutralized autoclave leach residue by cyanidation.

  • Valves for autoclaves – pressure oxidation ( POX)

    2018-9-27  is utilized is high pressure acid leaching (HPAL). HPAL is usually used in the recovery of nickel and cobalt. Figure2 shows the typical temperature and pressure ranges for POX and HPAL. Pressure oxidation (POX) 10 35 Min Pressure (Bar) Max pressure (Bar) 150 225 Min temperature (°C) Max temperature (°C) High pressure acid leaching (HPAL) 35 65

  • Basic Iron Sulphate in Pressure Oxidation Processing

    2015-12-16  oxidation or pressure oxidation . processes, in which the sulphide component of the host mineral is oxidized with oxygen to elemental sulphur, sulphur dioxide gas or sulphate ions. There are a great many operating plants around the world employing one or other of these 3 processes to oxidize sulphides ahead of a traditional gold recovery process.

  • Pressure Oxidation of a Refractory Sulfide

    2020-7-20  Pressure oxidation of the refractory sulfide/carbonaceous ores has gained world-wide acceptance. Compared with roasting, pressure oxidation yields higher gold extractions from ores or concentrates and enables better handling of environmentally sensitive impurities. Normally, gold is extracted from neutralized autoclave leach residue by cyanidation.

  • Oxidation of nickel sulfide SpringerLink

    The oxidation of nickel sulfide whose atomic fraction of sulfur,x s, is 0.40 to 0.44 was studied in a mixed O2-N2 gas stream at 923, 973, and 1023 K. The oxygen partial pressure was maintained at 2.0 x 104 Pa. In the oxidation of nickel sulfide ofx s = 0.40 and 0.41, a dense NiO layer was formed on the sulfide surface without the evolution of SO2 gas, because of the low sulfur activity.

  • Analysis of Pressure Variations in a Low-Pressure

    位置: 8600 Rockville Pike, Bethesda, MD
  • Pressure Oxidation Plants For Gold Mining - Machine

    High Pressure Acid Leach Pressure Oxidation. 2016-12-20Uranium Nickel Gold Copper Cobalt Rare earths Zinc High Pressure Acid Leach HPAL and Pressure Oxidation POX testing services provide a unique opportunity to evaluate and optimise the most economically viable process routes for the recovery of most metals such as nickel from lateritic ores and gold from refractory ores

  • Effects of Oxygen Partial Pressure on the Surface Tension ...

    2015-8-28  – Oxidation may have an impact of 10-30% on surface tension measurements3. – Causes a decrease in surface tension • Oxidation can occur at very low 𝑝𝑂 2 – Has been observed in the MSFC ESL as low as ~ 1x10-25 bar 𝑝𝑂 2 References: 1. Ozawa, S., et.al., Relationship of Surface Tension, Oxygen Partial Pressure,

  • oxidation test 的翻译结果--cnki翻译助手

    The deterioration of aluminide coating formed on two cast nickel-base superalloys by pack cementation or by vapour calorizing under reduced pressure has been investigated.To evaluate the coating stability, the oxidation tests were made by exposure to static air

  • High Pressure Acid Leach - Caldera Engineering

    High Pressure Acid Leach (HPAL) is a process used to extract nickel and cobalt from laterite ore bodies. The HPAL process utilizes elevated temperatures (roughly 255 degrees Celsius), elevated pressures (roughly 50 bar or 725 psi), and sulfuric acid to separate nickel and cobalt from the laterite ore.

  • 41 SULFIDES FROM THE DULUTH GABBRO LEACHING OF

    2019-8-20  FROM THE PRESSURE OXIDATION LEACHING OF BULK COPPER-NICKEL SULFIDES FROM THE DULUTH GABBRO By Blair R. Benner and Harlan B. Niles June 1999 Technical Report NRRI/TR-99/41 CMRL/TR-99-09 Natural Resources Research Institute University of Minnesota Duluth 5013 Miller Trunk Highway Duluth, MN 55811-1442 Coleraine Minerals Research Laboratory

  • Reversible Oxygenâ Driven Nickel Oxide Structural ...

    Reversible Oxygen-Driven Nickel Oxide Structural Transition on the Nickel(111)Surface at Near-Ambient Pressure MyungCheol Noh,[a, b] Jeongjin Kim,[a, b] WonHui Doh,[b] Ki-Jeong Kim,[c] and Jeong Young Park*[a, b] Introduction The control of oxide layersonmetal oxide materials for indus-trial applications has been attempted to take better advantage

  • Lecture 12 Mechanisms of Oxidation and Corrosion

    2013-3-31  or Pilling-Bedworth ratio = 1 (ration of oxide volume produced by oxidation to the volume of metal consumed by oxidation) 2. The oxide film should have good adherence, high-temperature plasticity to prevent fracture 3. The melting point of the oxide should be high 4. The oxide films should have a low vapor pressure and thermal coefficient of

  • Analysis of Pressure Variations in a Low-Pressure

    位置: 8600 Rockville Pike, Bethesda, MD
  • Characterization of Residue from the Pressure

    A bulk sulfide flotation process followed by oxidation pressure leaching resulted in high extractions (>98 %) of the copper and nickel in the flotation concentrate. During the leaching, the iron in the flotation concentrate leaches and precipitates as either hematite (crystalline or amorphous) or as a basic iron sulfate (jarosite).

  • Pressure Oxidation Plants For Gold Mining - Machine

    High Pressure Acid Leach Pressure Oxidation. 2016-12-20Uranium Nickel Gold Copper Cobalt Rare earths Zinc High Pressure Acid Leach HPAL and Pressure Oxidation POX testing services provide a unique opportunity to evaluate and optimise the most economically viable process routes for the recovery of most metals such as nickel from lateritic ores and gold from refractory ores

  • Ambient-Pressure XPS Study of a Ni–Fe Electrocatalyst

    2019-5-25  Chemical analysis of solid–liquid interfaces under electrochemical conditions has recently become feasible due to the development of new synchrotron radiation techniques. Here we report the use of “tender” X-ray ambient-pressure X-ray photoelectron spectroscopy (APXPS) to characterize a thin film of Ni–Fe oxyhydroxide electrodeposited on Au as the working electrode at different applied ...

  • Autoclave Technology

    With the right innovative and proprietary equipment designs, your pressure-oxidation needs can be effectively met. Our services are unique to your needs. We operate through the entire range of activities: feed-stock testing, construction material selection, advanced instrumentation, attention to safety, and operator-friendly plant layout.

  • The role of nickel in the oxidation resistance of tungsten ...

    2020-5-25  Analysis of the oxidation resistance up to temper-atures of 750°C allows one to conclude that increasing nickel contents in the films give rise to increasing oxida-Fig. 3. Isothermal oxidation curves of the W–N–Ni coatings in air. tion resistance. At 800°C an inversion was observed for the coatings W 70 N 15 Ni 15 and W 66 N 18 Ni 16 ...

  • Nickel–vanadium monolayer double hydroxide for

    2016-6-16  Water oxidation is a key component of water splitting, but more effective catalysts for the process are still required. Here the authors synthesize a monolayer nickel-vanadium layered double ...

  • Lecture 12 Mechanisms of Oxidation and Corrosion

    2013-3-31  or Pilling-Bedworth ratio = 1 (ration of oxide volume produced by oxidation to the volume of metal consumed by oxidation) 2. The oxide film should have good adherence, high-temperature plasticity to prevent fracture 3. The melting point of the oxide should be high 4. The oxide films should have a low vapor pressure and thermal coefficient of

  • 11_Effects of Small Additions of Copper and Copper + Nickel ...

    2014-8-4  11_Effects of Small Additions of Copper and Copper + Nickel on the Oxidation Behavior of Iron ... The air used had a water vapor partial pressure of 1.4 9 10-4 atm at 23 °C. Oxidized sample microstructures were investigated in a scanning electron microscope To ...

  • Nickel-Cobalt-Copper Conference

    2017-8-2  Stephen Barnett, Consultant (UK); Janne Seppälä, Mondo Minerals Nickel Oy (Finland) PRESSURE OXIDATION 397 LEACHING BEHAVIOR OF NI/CO MIXED SULFIDE BY USING PRESSURIZED OXIDATION 398 Shinichi Heguri, Satoshi Asano, Atsushi Idegami, Sumitomo Metal Mining Corporation (Japan) TACKLING IMPURITIES IN COPPER CONCENTRATES 406